/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.epl.expression;
import com.espertech.esper.epl.agg.service.AggregationMethodFactory;
import com.espertech.esper.epl.core.MethodResolutionService;
import com.espertech.esper.epl.core.StreamTypeService;
/**
* Represents the sum(...) aggregate function is an expression tree.
*/
public class ExprSumNode extends ExprAggregateNodeBase
{
private static final long serialVersionUID = 208249604168283643L;
private final boolean hasFilter;
/**
* Ctor.
* @param distinct - flag indicating unique or non-unique value aggregation
*/
public ExprSumNode(boolean distinct, boolean hasFilter)
{
super(distinct);
this.hasFilter = hasFilter;
}
public AggregationMethodFactory validateAggregationChild(StreamTypeService streamTypeService, MethodResolutionService methodResolutionService, ExprEvaluatorContext exprEvaluatorContext) throws ExprValidationException
{
Class childType = super.validateNumericChildAllowFilter(streamTypeService, hasFilter);
return new ExprSumNodeFactory(methodResolutionService, childType, super.isDistinct(), hasFilter);
}
protected String getAggregationFunctionName()
{
return "sum";
}
public final boolean equalsNodeAggregate(ExprAggregateNode node)
{
if (!(node instanceof ExprSumNode))
{
return false;
}
return true;
}
}